Aesthetics, economy, strength and utility are all important considerations in the design of eyeglass frames.
For vehicle drivers and sportsmen, the wide occlusions in the field of vision which frames present are undesirable and even dangerous.
In this last respect it is desirable that the lateral vision of the wearer be minimally impaired so that the eyeglass wearer and the driver of a vehicle can view passing or overtaking vehicles with minimal difficulty and the sportsman can see a sideways approaching opponent.
The further considerations of economy and strength also require that the eyeglasses be durable while economical to produce. At the same time, the frame should be of such a structure that they may be versatile and provide the basis for a variety of designs.
Various approaches have been proposed such as those set out below in the following U.S. patents, namely:
______________________________________ U.S. 2,730,924 De Angelis January 17, 1956 U.S. 1,825,503 T. H. Carow September 29, 1931 Des. 175,269 Nelson August 2, 1955 Des. 191,229 Boxer August 29, 1961 Des. 201,919 Simpson August 10, 1965 Des. 203,483 Thomas January 11, 1966 ______________________________________
The Carow, Simpson, De Angelis and Boxer structures, while they appear to be directed to similar problems, do not have the versatility of design nor economy which the present frame structure provides.